A fused ring compound and its applications

Abstract

This invention provides a fused-ring compound and its application. The fused-ring compound has the structure shown in Formula I. The fused-ring compound of this invention is used as a hole transport material, which can improve the efficiency of organic light-emitting elements, extend their lifetime, and reduce the driving voltage. Organic electroluminescent devices using the fused-ring compound of this invention as a hole transport material have lower driving voltage, higher current efficiency, and extended lifetime.

Description

[0001] This application is a divisional application of patent application number 202011310370.7, the original application being filed on November 20, 2020, and entitled "A Fused Ring Compound and Its Application - Applied to a Divisional Application". Technical Field

[0002] This invention belongs to the field of organic electroluminescent materials and relates to a fused ring compound and its applications. Background Technology

[0003] Organic light-emitting materials can be broadly classified according to their function into light-emitting materials, hole injection materials, hole transport materials, electron transport materials, and electron injection materials.

[0004] To date, amine derivatives with a carbazole backbone have been extensively studied for hole transport materials, but many problems remain regarding driving voltage, efficiency, and lifetime. Therefore, it is necessary to develop a novel hole transport material to improve the efficiency, extend the lifetime, and reduce the driving voltage of organic light-emitting elements. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a fused-ring compound and its applications. The fused-ring compound of the present invention, when used as a hole transport material, can improve the efficiency of organic light-emitting devices, extend their lifetime, and reduce the driving voltage.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] On one hand, the present invention provides a fused-ring compound having the structure shown in Formula I:

[0008]

[0009] in Each is independently selected from 5-30 member aromatic rings or heterocyclic aromatic rings.

[0010] R 1 R 2 Each of the following is independently selected from hydrogen, deuterium, substituted or unsubstituted C1-C10 straight-chain alkyl, substituted or unsubstituted C3-C10 branched alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl.

[0011] R 3 -R 6Each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C10 linear alkyl, substituted or unsubstituted C3-C10 branched alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, -L-NAr 1 Ar 2 、-L-SiR 7 R 8 R 9 、-LOR 10 、-LSR 11 ,

[0012] R 7 -R 11 Each independently selected from hydrogen, deuterium, substituted or unsubstituted C1-C10 linear alkyl, substituted or unsubstituted C3-C10 branched alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl,

[0013] R 3 -R 6 At least one is selected from -L-NAr 1 Ar 2 ,R 3 -R 6 Each independently exists or two adjacent ones form a ring,

[0014] Each L is the same or different and is selected from a single bond, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl,

[0015] Ar 1 、Ar 2 Each independently selected from substituted or unsubstituted C1-C10 linear alkyl, substituted or unsubstituted C3-C10 branched alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl,

[0016] The heteroatoms in the heteroaryl are selected from at least one of O, S, and N,

[0017] a, b, c, d are each independently an integer from 0 to 3;

[0018] When the above-mentioned groups have substituents, the substituents are independently selected from deuterium, halogen, nitro, cyano, R 12Substituted or unsubstituted C1-C4 alkyl groups, R 12 Substituted or unsubstituted C1-C4 alkoxy groups, R 12 Substituted or unsubstituted C6-C12 aryl, R 12 Substituted or unsubstituted C6-C12 aryloxy groups, R 12 Substituted or unsubstituted C6-C12 aromatic amino groups, R 12 Substituted or unsubstituted C3-C12 heteroaryl groups, R 12 Substituted or unsubstituted C3-C12 heteroarylamines;

[0019] R 12 Selected from deuterium, halogen, cyano, C1-C4 alkyl, C6-C12 aryl, and multiple R 12 Same or different.

[0020] The compound of the present invention has a fused ring structure as shown in Formula I, which gives the compound a suitable hole transport capability. The electrons and holes entering the light-emitting layer are balanced, which makes the organic electroluminescent device using it as a hole transport material have high efficiency, low driving voltage and extended service life.

[0021] Preferably, the Each ring is independently selected from benzene ring, naphthalene ring, phenanthrene ring, pyridine ring, indole ring, benzofuran ring, or benzothiophene ring, with benzene ring, naphthalene ring, or phenanthrene ring being preferred.

[0022] Preferably, the fused-ring compound is a compound having one of the following structures:

[0023]

[0024] The defined ranges for each group are the same as those in the compound shown in Formula I.

[0025] Preferably, the fused-ring compound is a compound having the structure shown in Formula II:

[0026]

[0027] Where X 1 X 2 Each is independently selected from single bonds, O, S, and NAr. 6 CAr 7 Ar 8 And one of them is a single bond.

[0028] Ar 6Substituted or unsubstituted C1-C10 linear alkyl, substituted or unsubstituted C3-C10 branched alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl,

[0029] Ar 7 -Ar 8 each independently selected from substituted or unsubstituted C1-C10 linear alkyl, substituted or unsubstituted C3-C10 branched alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C2-C10 alkenyl, substituted or unsubstituted C2-C10 alkynyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C-3-C30 heteroaryl;

[0030] The definitions of the remaining groups are the same as those in the compound shown in Formula I.

[0031] Preferably, the said Ar 1 、Ar 2 、Ar 6 、Ar 7 、Ar 8 each independently selected from substituted or unsubstituted groups as follows: pyridine, phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, phenylnaphthyl, fluorene, phenylfluorene, benzofluorene, dibenzofluorene, phenanthrene, phenylphenanthrene, anthracene, indene, triphenylene, pyrene, tetracene, perylene, chrysene, tetrabenaphthene, fluoranthene, spirobifluorene, furan, dibenzofuran, thiophene, dibenzothiophene, benzofuran, benzothiophene, isobenzofuran, pyridyl, carbazolyl or dihydroacridinyl; when the said group is substituted, the substituent is halogen, cyano, C1-C4 alkyl, C6-C12 aryl.

[0032] Preferably, the said Ar 1 Ar 2 Ar 6 Ar 7 Ar 8 each independently selected from substituted or unsubstituted groups as follows:

[0033]

[0034] R 13 is selected from methyl, ethyl, propyl, butyl, isopropyl, tert-butyl, phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, T is selected from NAr 3 、O、S、C Ar 4 Ar 5 ;

[0035] Ar3 Selected from phenyl, biphenyl, terphenyl, naphthyl, anthraceneyl, or phenanthrene;

[0036] Ar 4 -Ar 5 Each is independently selected from methyl, ethyl, propyl, butyl, isopropyl, tert-butyl, phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, Ar 4 -Ar 5 They can exist independently or be connected to form a ring.

[0037] When the substituent is a group as described above, the substituent is a halogen, cyano, C1-C4 alkyl, or C6-C12 aryl.

[0038] Preferably, the fused-ring compound is any one of the following compounds W-1 to W-156:

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049] The fused-ring compound of the present invention can be synthesized from starting material a and starting material b via the following synthetic route:

[0050]

[0051] The alkyl group described in this invention can be either straight-chain or branched. Optionally, the straight-chain alkyl group includes, but is not limited to, methyl, ethyl, propyl, and butyl, and the branched alkyl group includes, but is not limited to, isopropyl, 2-butyl, isobutyl, and tert-butyl.

[0052] The cycloalkyl groups mentioned in this invention include, but are not limited to, cyclopropane, cyclobutane, and cyclohexane.

[0053] The alkenyl group described in this invention refers to a monovalent substituent derived from a straight-chain or branched unsaturated hydrocarbon having one or more carbon-carbon double bonds and 2 to 40 carbon atoms. Examples include, but are not limited to, vinyl, allyl, isopropenyl, 2-butenyl, etc.

[0054] The aryl groups described in this invention include monocyclic, polycyclic, and fused-ring aryl groups, wherein the rings can be interrupted by short non-aromatic units (e.g., methylene). Preferably, the aryl group is selected from phenyl, biphenyl, triphenyl, naphthyl, binatyl, phenylnaphthyl, naphthylphenyl, fluorenyl, phenylfluorenyl, benzo[a]fluorenyl, dibenzo[a]fluorenyl, phenanthrene, phenylphenanthrene, anthracene, indene, triphenylene, pyrene, tetraphenyl, peryl, trefyl, fused tetraphenyl, fluoranyl, or spirodifluorenyl.

[0055] The heteroaryl groups described in this invention include monocyclic, polycyclic, and fused-ring types, and the rings can be interrupted by short non-aromatic units (e.g., methylene, O, S, N). Preferably, the heteroaryl group is selected from furanyl, phenylthio, pyrroloyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetraazinyl, triazolyl, tetraazolyl, furazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, benzofuranyl, benzothiopheneyl, isobenzofuranyl, dibenzofuranyl, dibenzothiopheneyl, benzimidazolyl, benzothiazolyl, benzoisothiazolyl, benzoisooxazolyl, benzooxazolyl, isoindolyl, indolyl, inzolyl, benzothiadiazolyl, quinolinyl, isoquinolinyl, cyclolinyl, quinazolinyl, quinoxolinyl, carbazole, phenoxazinyl, phenthiazinyl, phenanthidyl, benzo-m-dioxacyclopentenyl, or dihydroacridinyl.

[0056] On the other hand, the present invention provides a hole transport material, which includes any one or a combination of at least two of the fused ring compounds described above.

[0057] On the other hand, the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising a first electrode, a second electrode, and an organic layer located between the first electrode and the second electrode, the organic layer comprising any one or a combination of at least two of the fused ring compounds described above.

[0058] Preferably, the organic layer includes a hole transport layer and / or a light-emitting auxiliary layer.

[0059] Preferably, the material of the hole transport layer includes any one or a combination of at least two of the fused ring compounds described above.

[0060] Preferably, the light-emitting auxiliary layer comprises any one or a combination of at least two of the fused-ring compounds described above.

[0061] On the other hand, the present invention provides an organic electroluminescent product, which includes the organic electroluminescent device as described above.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] The fused-ring compound of the present invention, when used as a hole transport material, can improve the efficiency of organic light-emitting elements, extend their lifetime, and reduce the driving voltage. Organic electroluminescent devices using the fused-ring compound of the present invention as a hole transport material have lower driving voltage, higher current efficiency, and extended lifetime. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the structure of the organic electroluminescent device of the present invention, wherein 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, 5 is a light-emitting layer, 6 is an electron transport layer, 7 is an electron injection layer, and 8 is a cathode. Detailed Implementation

[0065] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0066] Synthesis Examples

[0067] The synthesis method is as follows:

[0068]

[0069] Synthesis of intermediate 1-W-1: In a 100 mL three-necked flask under nitrogen protection, starting material 1 (3.38 g, 0.01 mol) and anhydrous THF (25 mL) were added, and the reaction mixture was cooled to -78°C. Under stirring, n-butyllithium (0.011 mol) was added, and the reaction was carried out at this temperature for 1 hour. Acetone (0.58 g, 0.01 mmol) was dissolved in 10 mL of anhydrous tetrahydrofuran and added dropwise to the reaction flask. After the reaction was complete at room temperature, water was added to the reaction system, followed by extraction with dichloromethane. The resulting extract was dried over magnesium sulfate, filtered, and evaporated to dryness. The crude product was purified by chromatography (ethyl acetate / n-hexane, 1 / 10) to give intermediate 1-W-1 (1.36 g, 43% yield).

[0070] The following compounds were prepared using a similar method.

[0071]

[0072]

[0073] Synthesis of intermediate 2-W-1: Intermediate 1-W-1 (3.16 g, 0.01 mol) and anhydrous THF (35 mL) were added to a 100 mL three-necked flask under nitrogen protection, and the reaction mixture was cooled to -78 °C. Under stirring, n-butyllithium (0.011 mol) was added, and the reaction was carried out at this temperature for 1 hour. Starting material 2 (2.58 g, 0.01 mmol) was dissolved in 20 mL of anhydrous tetrahydrofuran and added dropwise to the reaction flask. After the reaction was complete at room temperature, water was added to the reaction system, and the mixture was extracted with dichloromethane. The resulting extract was dried over magnesium sulfate, filtered, and evaporated to dryness. The crude product was purified by chromatography (ethyl acetate / n-hexane, 1 / 10) to give intermediate 2-W-1 (1.36 g, 36% yield).

[0074] The following compounds were prepared using a similar method.

[0075]

[0076]

[0077]

[0078] Synthesis of intermediate 3-W-1: In a 100 mL three-necked flask, intermediate 2-W-1 (4.96 g, 0.01 mol) was added, along with acetic acid (30 mL) and hydrochloric acid (2 mL). The mixture was stirred under reflux for 4 hours. After the reaction was complete, the mixture was washed with a saturated sodium bicarbonate aqueous solution. The organic layer was dried with anhydrous magnesium sulfate to remove the organic solvent. The crude product was recrystallized from tetrahydrofuran:ethanol = 1:4 to obtain intermediate 3-W-1 (1.93 g, yield 42%).

[0079] The following compounds were prepared using a similar method.

[0080]

[0081]

[0082]

[0083] Synthesis of W-1: In a 100 mL three-necked flask under nitrogen protection, intermediate 3-W-1 (0.01 mol), diphenylamine (0.01 mol), dioxane (30 mL), palladium acetate (5 mmol), tri-tert-butylphosphine (8 mmol), and cesium carbonate (0.02 mol) were added. The reaction was carried out overnight at 100 °C. After the reaction was completed, water was added to quench the reaction, and the mixture was extracted with dichloromethane. The organic layer was dried over anhydrous magnesium sulfate to remove the organic solvent. The crude product was purified by chromatography (ethyl acetate / n-hexane, 1 / 10) to give W-1 (4.45 g, yield 81%).

[0084] Elemental analysis: C42H31N, theoretical values: C 91.77, H 5.68, N 2.55, measured values: C 91.75, H 5.70, N 2.55;

[0085] HRMS(ESI)m / z(M+): Theoretical value: 549.2457, measured value: 549.2464.

[0086] The following compounds were prepared using a similar method.

[0087]

[0088]

[0089]

[0090] Synthesis of W-60: A 100 mL three-necked flask was placed with a stir bar and a reflux tube attached. Nitrogen gas was introduced, and intermediate 3-W-60 (4.60 g, 0.01 mol), starting material 4 (4.54 g, 0.01 mol), potassium carbonate (0.015 mol), tetrakis(triphenylphosphine)palladium (0.5 mmol), toluene (40 mL), and water (10 mL) were added. The reaction was carried out at 60 °C for 12 hours under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature and quenched with 3 mL of ice water. The mixture was extracted with dichloromethane (3 × 30 mL). The resulting extract was dried with magnesium sulfate, filtered, and evaporated to dryness. The crude product was purified by chromatography (ethyl acetate / n-hexane, 1 / 10 (v / v)) to obtain W-60 (6.48 g, 82% yield).

[0091] The following compounds were prepared using a similar method.

[0092]

[0093] Testing: The intermediates and compounds in this invention were analyzed and detected using a mass spectrometer (model OrbitrapID-XTribrid) and an organic elemental analyzer (model PE2400Ⅱ).

[0094]

[0095]

[0096] Device Examples

[0097] This embodiment provides an organic electroluminescent device, such as... Figure 1 As shown, it includes an anode 2, a hole injection layer 3, a hole transport layer 4, a light-emitting layer 5, an electron transport layer 6, an electron injection layer 7, and a cathode 8, which are sequentially stacked on a substrate 1.

[0098] Among them, anode 2 is made of ITO material;

[0099] The hole injection layer 3 material is formed by doping with compound PD and compound NPB with the structure shown below: wherein the mass ratio of PD to NPB doping is 3:97;

[0100]

[0101] The hole transport layer 4 material is selected from the compounds prepared in the synthesis examples or the compounds in the comparative examples (as shown in Table 3):

[0102] The luminescent layer 5 is formed by co-doping of a host material and a guest material, wherein the host material is CBP and the guest material is the compound Ir(piq)2(acac), with a mass ratio of 95:5 between the host and guest materials. The chemical structures of the compounds CBP and Ir(piq)2(acac) are shown below:

[0103]

[0104] The electron transport layer 6 material is formed by doping the compound BPhen with the compound LiQ, as shown below: wherein the mass ratio of BPhen to LiQ dopant is 1:1.

[0105]

[0106] The electron injection layer 7 material is selected from the compound LiQ with the following structure:

[0107]

[0108] The cathode 8 is made of a mixture of metallic Mg and Ag, with a mass ratio of Mg to Ag of 9:1.

[0109] The fabrication of the above-mentioned organic electroluminescent device includes the following steps:

[0110] 1) Substrate cleaning:

[0111] The glass substrate 1 coated with ITO transparent electrodes was ultrasonically treated in an aqueous cleaning agent (the composition and concentration of the aqueous cleaning agent: ethylene glycol solvent ≤10wt%, triethanolamine ≤1wt%), rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent (volume ratio 1:1), baked in a clean environment until all moisture was removed, and then cleaned with ultraviolet light and ozone.

[0112] 2) Evaporation:

[0113] The glass substrate 1 with anode 2 was placed in a vacuum chamber and evacuated to a vacuum level of 1×10⁻⁶. -6 Up to 2×10 -4Pa, the hole injection layer 3 material is vacuum-deposited on the above-mentioned anode layer film by co-evaporation, wherein the PD and NPB are adjusted at a mass ratio, the total evaporation rate is 0.1 nm / s, and the evaporation thickness is 10 nm.

[0114] 3) A hole transport layer 4 is deposited on top of the hole injection layer 3 at a deposition rate of 0.1 nm / s and a film thickness of 80 nm.

[0115] 4) Evaporate the light-emitting layer 5 on the hole transport layer 4, and vacuum evaporate the light-emitting host material and guest material in a co-evaporation manner. The evaporation rate of the host material and guest material is adjusted according to the mass ratio. The total evaporation rate is 0.1 nm / s and the total evaporation film thickness is 40 nm.

[0116] 5) An electron transport layer 6 is vacuum-deposited on the light-emitting layer 5. The deposition rate is adjusted according to the mass ratio of compound BPhen to LiQ. The total deposition rate is 0.1 nm / s and the total deposition film thickness is 30 nm.

[0117] 6) An electron injection layer 7 is vacuum-deposited on the electron transport layer 6 at a deposition rate of 0.05 nm / s and a total deposition thickness of 1 nm.

[0118] 7) Evaporate cathode 8 onto electron injection layer 7. Adjust the evaporation rate according to the mass ratio of Mg and Ag metals. The total evaporation rate is 0.1 nm / s and the total evaporation film thickness is 80 nm.

[0119] The compounds used in Comparative Examples 1-4 are as follows:

[0120]

[0121]

[0122] Test Example 1

[0123] 1. Determining the thermal decomposition temperature of compounds

[0124] Determination of thermal decomposition temperature of compounds: The thermal decomposition temperature (Td) of the nitrogen-containing heterocyclic compounds of the present invention was tested using a thermogravimetric analyzer (TA TGA55, USA). The test range was from room temperature to 600°C, the heating rate was 10°C / min, and the temperature at which the weight loss was 5% was defined as the decomposition temperature under a nitrogen atmosphere. The test results are shown in Table 1.

[0125] Table 1 Thermal decomposition temperatures of nitrogen-containing heterocyclic compounds

[0126] compound <![CDATA[T d (℃)]]> W-1 307 W-69 371 W-60 440 W-67 439 W-82 453 W-101 361 W-112 418 W-129 367 W-137 415 W-144 387

[0127] 2. LUMO and HOMO energy level testing

[0128] The LUMO and HOMO energy levels of the nitrogen-containing heterocyclic compounds prepared in Examples 1-13 were measured using cyclic voltammetry (CV Shanghai Chenhua CHI-600E) on an electrochemical workstation. Platinum wire (Pt) was used as the counter electrode, and silver / silver chloride (Ag / AgCl) was used as the reference electrode. Measurements were performed at a scan rate of 100 mV / s in a dichloromethane electrolyte containing 0.1 M tetrabutylammonium hexafluorophosphate under a nitrogen atmosphere. Ferrocene was used for potential calibration, and the absolute energy level of ferrocene under vacuum was set to -4.8 eV.

[0129] HOMO 能阶 = -e(Eox-E 1 / 2,ferrocene )+(-4.8)eV

[0130] LUMO 能阶 =-e(E re -E 1 / 2,ferrocene )+(-4.8)eV;

[0131] Where E ox E is the oxidation potential. re E is the reduction potential. 1 / 2,ferrocene This is the potential of ferrocene.

[0132] Triple-state energy level testing conditions: The compound to be tested was prepared into a solution using toluene as a solvent (concentration 2*10). - 5 The above solution (mol / L) was tested at -78°C using a fluorescence spectrophotometer (Hitachi F-4600). E T1 (eV) represents the triplet energy level of the compound, which is calculated using the following formula.

[0133] E T1 =1240 / shortest absorption wavelength.

[0134] The test results are shown in Table 2.

[0135] Table 2 Energy level test results of nitrogen-containing heterocyclic compounds

[0136]

[0137] Test Example 2

[0138] Instruments: The current, voltage, brightness, emission spectrum and other characteristics of the device were tested simultaneously using a PR 650 spectral scanning luminance meter and a Keithley K 2400 digital source meter system;

[0139] Test conditions: Current density 20 mA / cm² 2 , room temperature.

[0140] Lifetime test: Record the time (in hours) when the device brightness drops to 98% of its original brightness.

[0141] The organic electroluminescent devices provided in Device Examples 1-9 and Comparative Examples 1-2 were tested, and the results are shown in Table 3:

[0142] Table 3 Device performance test results

[0143] Device Examples Hole transport materials Light-emitting auxiliary layer Voltage (V) Current efficiency cd / A Lifespan (h) Device Example 1 W-1 / 4.1 19 57 Device Example 2 W-1 W-69 4.0 21 89 Device Example 3 W-60 / 4.0 20 67 Device Example 4 W-67 / 3.9 23 65 Device Example 5 W-82 / 4.0 21 72 Device Example 6 W-101 / 4.0 22 64 Device Example 7 W-112 / 4.0 20 82 Device Example 8 W-129 / 3.9 24 91 Device Example 9 W-137 / 4.0 26 76 Device Example 10 W-144 / 4.0 22 75 Device Comparison Example 1 Ref-1 / 4.2 16 28 Device Comparison Example 2 Ref-2 / 4.2 17 25 Device Comparison Example 3 Ref-3 / 4.3 16 17 Device Comparison Example 4 Ref-4 / 4.4 14 21

[0144] As can be seen from Table 3, Excessive rigidity and planarity of the structure cause charge carriers to move horizontally and reduce their movement in the vertical direction. This results in a decrease in the number of charge carriers entering the light-emitting layer, reduced device efficiency, increased driving voltage, and shortened lifetime.

[0145] The weak hole transport capability leads to an imbalance in the transport of holes and electrons, resulting in reduced device efficiency, increased driving voltage, and shortened lifespan.

[0146] The applicant declares that the present invention is illustrated by the above embodiments to demonstrate the fused ring compounds and their applications, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A fused-ring compound, characterized in that, The fused-ring compound is a compound having one of the following structures: ;R 1 R 2 It is methyl, R 3 -R 6 It is hydrogen or methoxy; Each L may be the same or different, and is selected from single-bonded, substituted or unsubstituted C6-C30 aryl groups, wherein the substituents are independently selected from deuterium, halogen, nitro, cyano, C1-C4 alkyl, C1-C4 alkoxy, C6-C12 aryl, C6-C12 aryloxy, and C3-C12 heteroaryl. The Ar 1 Ar 2 Each of the following groups, whether substituted or unsubstituted, is independently selected: ； R 13 Selected from methyl, ethyl, propyl, butyl, isopropyl, tert-butyl, phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, and T is selected from NAr. 3 、O、S、C Ar 4 Ar 5 ; Ar 3 Selected from phenyl, biphenyl, terphenyl, naphthyl, anthraceneyl, or phenanthrene; Ar 4 -Ar 5 Each is independently selected from methyl, ethyl, propyl, butyl, isopropyl, tert-butyl, phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthrene, Ar 4 -Ar 5 They can exist independently or be connected in a loop; When the substituent is a group substituted as described above, the substituent is a halogen, cyano, C1-C4 alkyl, or C6-C12 aryl; a, b, c, and d are each independent integers between 0 and 3.

2. The fused-ring compound according to claim 1, characterized in that, The fused-ring compound is any one of the following compounds: 。 3. A hole transport material, characterized in that, The hole transport material includes any one or a combination of at least two of the fused ring compounds as described in claim 1 or 2.

4. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes a first electrode, a second electrode, and an organic layer located between the first electrode and the second electrode, wherein the organic layer includes any one or a combination of at least two of the fused ring compounds as described in claim 1 or 2.

5. The organic electroluminescent device according to claim 4, characterized in that, The organic layer includes a hole transport layer and / or a light-emitting auxiliary layer.

6. The organic electroluminescent device according to claim 5, characterized in that, The material of the hole transport layer includes any one or a combination of at least two of the fused ring compounds as described in claim 1 or 2.

7. The organic electroluminescent device according to claim 6, characterized in that, The light-emitting auxiliary layer comprises any one or a combination of at least two of the fused ring compounds as described in claim 1 or 2.

8. An organic electroluminescent product, characterized in that, The organic electroluminescent product includes the organic electroluminescent device as described in any one of claims 4-7.

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